This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We propose to evaluate the short-term effects of feeding infants with abdominal wall defects (AWD) with a diet of entirely human milk protein compared with a diet including cow s milk protein. Infant s mothers will provide their own breast milk which will be used when available. The remainder of the diet will consist of donor human milk. If needed, human milk fortification will be accomplished using a human milk based human milk fortifier (HMF). Comparisons will be based on the primary endpoint of days of total parenteral nutrition (TPN) as well as days to full enteral feeding (150 mL/kg/day), culture-proven sepsis, necrotizing enterocolitis (NEC), death, growth, cholestasis, peak alkaline phosphatase activity, and incidence of feeding intolerance. The comparison group will be a matched group of infants (2 historical controls for each enrolled infant) cared for between 2006-2009. Overall comparisons will also be made between infants from 2006-2009 and the current cohort. We hypothesize that infants with AWD that are fed exclusively human milk protein (vs cow s milk protein) will have improved feeding tolerance (as defined by days to full feeds and total TPN days) and have less complications of long term parenteral nutrition (such as infection, TPN related liver disease and death). We will conduct a case control, cohort study to evaluate the potential short-term benefits of using human milk based nutrition for infants with AWD. Infant s mothers will provide their own breast milk (mother s own milk, MOM) which will be used when available. The remainder of the diet will consist of donor human milk. If needed, human milk fortification will be accomplished using a human milk based human milk fortifier (HMF). The DHM and human milk based HMF will be provided by Prolacta Biosciences, Inc. Outcomes will be compared to historical controls from protocol H-23634. Comparisons will be based on the primary endpoint of days of total parenteral nutrition (TPN) as well as days to full enteral feeding (150 mL/kg/day), culture-proven sepsis, necrotizing enterocolitis (NEC), death, growth, cholestasis, peak alkaline phosphatase activity (AP), and incidence of feeding intolerance. The comparison group will be a matched group of infants (2 historical controls for each enrolled infant) cared for between 2006-2009. Overall comparisons will also be made between infants from 2006-2009 and the current cohort.